-oxygenated 21-dialkylamino-20-methyl-5alpha-pregn-17(20)-dien-3-ones and congeners

ABSTRACT

PREPARATION 3-OXYGENATED 21-DIALKYLAMINO-20-,ETHYL -5A - PREGN -17(20) -DIEN-3-ONES AND CONGENERS, AND THE VALUABLE ANTUVIOTIC OROOERTIES THEREOF, ARE DISCLOSED.

United States Patent Ofice 3,816,480. Patented June 11,, 1974 3,816,480 S-OXYGENATED 21-DIALKYLAMlNO-20-METHYL- 5a-PREGN-17(20)-DIEN-3-0NES AND CONGENERS George R. Lenz, Glenview, Ill., assignor to G. D. Searle & Co., Chicago, Ill. N Drawing. Filed July 30, 1973, Ser. No. 383,526 Int. Cl. C07c 169/22 US. Cl. 260-3971 14 Claims ABSTRACT OF THE DISCLOSURE Preparation of 3-oxygenated 2l-dialkylamino-20-methyl 50c pregn 17(20) dien-S-ones and congeners, and the valuable antibiotic properties thereof, are disclosed.

This invention relates to 3-oxygenated 21-dialkylamino 20 methyl m pregn 17(20) diene 3 Ones and congeners, and to processes for the preparation thereof. More particularly, this invention provides chemical compounds of the formula H3 0 C CH Z N (lower alkyl) wherein Z represents B-(lower alkanoyloxy)methylene, ,8- hydroxymethylene, or carbonyl, and Z represents methylene or carbonyl.

By lower alkyl is meant methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert.-butyl, phenyl, neopentyl, hexyl isohexyl, heptyl, and like monovalent, saturated, acyclic, straightor branched-chain, hydrocarbon groupings of the formula wherein n represents a positive integer less than 8. Lower alkanoyloxy as used herein designates a radical of the formula 0 I lower alkyl-J-O- Equivalent to the basic amines comprehended hereby (compounds of the introductory formula in wh1ch Z' represents methylene) for the purposes of this invention are corresponding acid addition salts having the formula C C (C H 0 HQN (lower alkyl) 2 a tivity includes the capacity to inhibit the growth of bacteria such as Bacillus subtilis and Erwinia sp.; protozoa such as T richomonas vaginalis; fungi such as Tricho'phyton mentagrophytes, Candida albicans, Fusarium sp., and Verticillium albo-atrum; and algae such as Clzlorella vulgaris.

The amides to which this invention relates (compounds of the introductory formula in which Z represents carbonyl) are useful both as intermediates to the congeneric amines and as antibacterial agents. They share, for example, the capacity of the aforesaid amines to inhibit the growth of Bacillus subtilis.

Standardized tests for the foregoing antibiotic activity are described in U.S. 3,682,951. 21-Diethylamino-20- methyl 5a pregn 17(20) en 3 one hydrochloride, the product of Example 11 hereinafter, was found active in these tests at 10 mcgm. per ml. against T. mentagrophytes, C. albicans, V. albo-atrum, and C. vulgaris; at mcgm. per ml. against B. subtilis and Erwinia sp.; and at 1000 mcgm. per ml. against T. vaginalis and Fusarium sp. 3B Acetox 21 diethylamino 20 methyl 5a pregn- 17(20)ene hydrochloride, the product of Example 10(B), and 21 diethylamino 20 methyl 5a pregn 17(20)- en-3-ol hydrochloride monohydrate, the product of EX- ample 9(A), were especially potent in respect of Erwinia sp. and C. vulgaris, respectively, being active at 1 mcgm. per ml. in the tests referred to. N,N Diethyl 35 hydroxy 5a pregn 17(20) ene 20 carboxamide and N,N-diethyl 3 oxo 5a pregn 17(20) ene-ZO-carboxamide, the products of Examples 5 and 7, respectively, were found to have about the same order of activity versus B. subtilis as 2l-diethylamino 20 methyl 5apregn-l7 (20) -en-3-one hydrochloride.

Those skilled in the art will recognize that observations of activity in standardized tests for particular biological effects are fundamental to the development of valuable new drugs, both veterinary and human.

The compounds of this invention can be prepared as follows: A 3/8-(lower alkanoyloxy)-5a-androstan-17-one is contacted with an N,N-di(lower alkyD-l-propynylamine in the presence of boron trifluoride etherate and dioxane, affording a 3fi-(lower alkanoyloxy)-N,N-di- (lower alkyl)-5a-pregn-17(20)-ene-20-carboxamide. The ester linkage is cleaved by contacting with aqueous methanolic potassium carbonate, and the resultant 3fi-hydroxy- N,N-di(lower alkyl) 5a pregn-17(20)-ene-20-carboxamide is oxidized via acetonic Jones reagent (a mixture of chromium trioxide, sulfuric acid, and water) to an N,N di(lower alkyl)-3-oxo-5a-pregn-l7 (20)-ene-20-carboxamide. The 3-keto group in the latter compound is protected by condensation with triethyl orthoformate in the presence of p-toluenesulfonic acid monohydrate and dioxane, the resultant 3-ethoxy-N,N-di(lower aIkyD-Sapregna-3,17(20)-diene 20 carboxamide is heated with lithium tetrahydroaluminate(l-) in tetrahydrofuran whereby the amidic oxygen is reduced, and the 21-di- (lower alkyl)amino-3-ethoxy 20 methyl-5a-pregn-3, 17(20)-diene thus obtained is converted to a 21-di(lower alkyl)amino 20 methyl-5a-pregn-17(20)-en-3-one by heating with aqueous hydrochloric acid. From a 3,8-(lower alkanoyloxy) N,N di(lower alkyl)-5a-pregn-17(20)- ene-20-carboxamide, on heating in dioxane with lithium tetrahydroaluminate(l-), a 21-di(lower alkyl)arnino-20- methyl-5a-pregn-17(20)-en-3;3-ol eventuates. Contacting such 35-01 in a mixture of chloroform and pyridine with an anhydride ofthe formula (lower alkanoyl) O affords a 2l-di(lower alkyl)amino-3fl(lower alkanoyloxy) -20-methyl-5 a-pregn-17 (20) -ene.

The basic amines of this invention are converted to the equivalent acid addition salts hereof by admixture with 1 equivalent of any of various inorganic and strong organic acids wherein the anion is defined by X above. The salts, in turn, are recon'verted to the basic amines upon contacting with excess alkali.

The following examples describe in detail compounds illustrative of the present invention and methods which have been devised for their preparation. It will be apparent to those skilled in the art that many modifications, both of materials and of methods, may be practiced without departing from the purpose and intent of this disclosure. Throughout the examples hereinafter set forth, temperatures are given in degrees centigrade and relative amounts of materials in parts by weight, except as otherwise noted.

EXAMPLE 1 3 3-acetoxy-N,N-dimethyI-SOL-pregn-17(20)-ene-20- carboxamide To a solution of 50 parts of 3B-acetoxy-5a-androstan- 17-0ne and 3 parts of boron trifluoride etherate in 100 parts of dioxane is added, with stirring, a solution of 25 parts of N,-N-dimethyl-1propynylamine in 50 parts of dioxane. The reaction mixture becomes very hot and turns red. When the heat abates, solvent is removed by vacuum distillation; the residue is taken up in benzene; and the benzene solution is chromatographed on silica, using benzene and mixtures thereof with increasing amounts of ethyl acetate as developing solvents. From an eluate comprising 5% ethyl acetate in benzene, on evaporation of solvent, 3;8-acetoxy-N,N- dimethyI-Sapregn-17(20)-ene-20-carboxamide is obtained as the residue. The product has the formula H O (IHCHa) ON (CH3)I H: C O O I EXAMPLE 2 v 3 fl-acetoxy-N,N-diethyl-5 a-pregn-17 (20)-ene-20- carboxamide To a solution of 50 parts of 3B-acetoxy-5a-androstan- 17-one and 3 parts of boron trifluoride etherate in 100 parts of dioxane is added, with stirring, a solution of 25 parts of N,N-diethyl-1-propynylamine in parts of dioxane. Stirring is continued for /2 hour following this addition, whereupon a further parts of N,N-diethyl-1 propynylamine and 5 parts of boron trifluoride etherate are consecutively introduced. Heat is evolved and the reaction mixture becomes dark red. Solvent is removed by vacuum distillation; the residue is taken up in benzene; and the benzene solution is chromatographed on silica gel, using benzene and mixtures thereof with increasing amounts of ethyl acetate as developing solvents. From an eluate comprising 5% ethyl acetate in benzene, on evaporation of solvent, 3fi-acetoxy-N,N-diethyl-5apregn-17(20)-ene-20-carboxamide melting at 142-144 is obtained as the residue.

EXAMPLE 3 N,N-Diethyl-3 B-propionyloxy-5a-pregn 17(20)-ene-20-carboxamide To a solution of 50 parts of 3,l3-propionyloxy-5a-androstan-17-one and 3 parts of boron trifluoride etherate in 100 parts of dioxane is added, with stirring, a solution of parts of N,N-diethyl-l-propynylamine in parts of dioxane. Stirring is continued for /2 hour after this addition is complete, whereupon a further 5 parts of boron trifluoride etherate and 20 parts of N,N-diethyl-1-propynylamine are consecutively introduced. Solvent is then removed by vacuum distillation and the residue is taken up in benzene. The benzene solution is chromatographed on silica gel, using benzene and mixtures thereof with increasing amounts of ethyl acetate as developing solvents. From an eluate comprising 5% of ethyl acetate in benzene, on evaporation of solvent, N,N-diethyl-3 8-propionyloxy-5a-pregn-17(20)-ene-20-carboxamide is obtained as the residue.

EXAMPLE 4 3 p-HydrQXy-NN-dimethyI-S a-pre gn- 17(20)-ene-20-carboxamide To a solution of 5 parts of 3fl-acetoxy-N,N-dimethyl- 5a-pregn-17(20)-ene 20 carboxamide in parts of methanol is added 20 parts of aqueous 25% potassium carbonate. The resultant mixture is stirred at room temperatures overnight, then extracted with chloroform. The chloroform extract is washed with water, dried over anhydrous sodium sulfate, and stripped of solvent by vacuum distillation. The residue is 35-hydroxy-N,N-dimethyl- Soc-pregn-17(20)ene-20-carboxamide.

EXAMPLE 5 N,N-Diethy1-3 B-hydrOXy-Su-pregn- 17(20)-ene-20-carboxamide A solution of 5 parts of 3,B-acetoxy-N,N-diethyl-5apregn-l7(20)-ene-20-carboxamide in a mixture of 20 parts of aqueous 25 potassium carbonate with 100 parts of methanol is stirred overnight, then poured into 100 parts of chloroform. The chloroform phase is separated, and the aqueous phase is washed with an additional 100 parts of chloroform. The two chloroform solutions are combined and washed with water, then dried over anhydrous sodium sulfate, and finally stripped of solvent by vacuum distillation. The residue, crystallized from a mixture of ethyl acetate and petroleum ether, is N,N-diethyl-3fl-hydroxy-5a-pregn-17(20)-ene 2O carboxamide melting at 203-205".

EXAMPLE 6 N,N-Dimethyl-3 -oxo-5a-pregn- 17( 20 -ene-20-carboxamide To a solution of 1 part of 3,8-hydroxy-N,N-dimethyl-Sapregn-17(20)-ene-20-carboxan1ide in 100 parts of acetone is added 1 part of Jones reagent (a mixture prepared by dissolving approximately 133 parts of chromium trioxide in 250 parts of Water and consecutively adding 196 parts of concentrated sulfuric acid and water q.s. 500 m1.). Excess reagent is quenched with 2-propanol, and to the resultant solution is added 500 parts of Water. Acetone is removed by vacuum distillation, whereupon N,N-dimethyl-3-oxo-5a-pregn-17(20)-ene 20 carboxamide precipitates in the distilland. The product is isolated by filtration and dried in air.

EXAMPLE 7 N,N-Diethyl-3-oxo-5wpregn-17(20) ene-ZO-carboxamide To a solution of 1 part of N,N-diethyl-3p-hydroxy-5apregn-17(20)-ene-20-carboxamide in 100 parts of acetone is added 1 part of Jones reagent. Excess reagent is quenched with 2-propanol, and to the resultant green solution is added 500 parts of water. Acetone is removed by vacuum distillation, whereupon N,N-diethy1 3 oxo-5apregn-17(20)-ene-20-carboxamide precipitates in the distilland. The product, isolated by filtration and dried in air, is obtained thus as colorless crystals melting at 137-140".

EXAMPLE 8 2l-Dimethylamino-20-methyl-Six-pregn- 17 (20 )-en-3,B-ol hydro chloride To a solution of 5 parts of 3B-acetoxy-N,N-dimethyl- 5u-pregn-17(20)-ene-20-carboxamide in 150 parts of tetrahydrofuran is added 3 parts of lithium tetrahydroaluminate(1-). The resultant mixture is heated at the boiling point under reflux overnight, whereupon parts of ethyl acetate is introduced. The mixture thus obtained is partitioned between 1000 parts of 5% hydrochloric acid and 2000 parts of chloroform. The chloroform phase is separated, dried over anhydrous sodium sulfate, and stripped of solvent by vacuum distillation. The residue is 21-dimethylamino 20 methyl-5a-pregn-l7(20)-en-35-ol hydrochloride, which is further purified by trituration with boiling ethyl acetate. The product has the formula EXAMPLE 9 To a solution of 5 parts of 3 8-acetoxy-N,N-diethyl-5apregn-17(20)-ene-20-carboxamide in 150 parts of tetrahydrofuran is carefully added 3 parts of lithium tetrahydroaluminate(1-). The resultant solution is heated at the boiling point overnight, whereupon 5 parts of ethyl acetate is introduced. The mixture thus obtained is partitioned between 1000 parts of 5% hydrochloric acid and 2000 parts of chloroform. The chloroform phase is separated, dried over anhydrous sodium sulfate, and stripped of solvent by vacuum distillation. The residue is 21-diethylamino-ZO-methyl-Sa-pregn-17(20)-en 3,8 ol hydrochloride monohydrate which, further purified by trituration with boiling ethyl acetate, is obtained as colorless crystals melting at approximately 265-266.

(B) 21-Diethylamino-20-methyl-5a-pregn-17 (20)- en-3p-ol To a solution of 1 part of 2l-diethylamino-20-methyl- 5a-pregn-l7(20)-en-3B-ol hydrochloride monohydrate in 100 parts of water is added 5 parts of potassium carbonate. The resultant mixture is extracted with 100 parts of chloroform. The chloroform extract is dried over anhydrous sodium sulfate and stripped of solvent by vacuum distillation. The residue is 2l-diethylamino-ZO-rnethyl-Sa-pregn- 17'(20)-en-318-0l which, crystallized from aqueous 10% methanol, is obtained as colorless crystals melting at 148- EXAMPLE 10 (A) 3,3-Acetoxy-21-diethylamino-20-methyl-5a-pregnl7(20)-ene To a solution of 1 part of 21-diethylamino-20-methy1- 5m-pregn-17(20)-en-3fl-ol in 10 parts of chloroform is added 8 parts of acetic anhydride and 10 parts of pyridine. The resultant mixture is allowed to stand at room temperatures overnight, whereupon 25 parts of methanol is introduced. Solvents are then removed by vacuum distillation, and to the residue is consecutively added 100 parts of water and 5 parts of potassium carbonate. Insoluble solids are filtered out and taken up in ethyl acetate. The ethyl acetate solution is treated with decolorizing charcoal,

6 filtered, and stripped of solvent by vacuum distillation. The residue is 3fi-acetoxy-2l-diethylamino-20-methyl-5otpregn-17(20)-ene which, recrystallized from methanol, is obtained as colorless crystals melting at 131-133".

(B) 3;6-Acetoxy-21-diethylamino-20-methy1-5a-pregn- 17 (20) -ene hydrochloride T o a solution of 1 part of 3fi-acetoxy-2l-diethylarnino- 20-methyl-5a-pregn-17(20)-cue in parts of chloroform is added 100 parts of 5% hydrochloric acid. The resultant mixture is stirred and then separated into the two component phases. The aqueous phase is extracted with 700 parts of chloroform, and this extract is combined With the original chloroform phase. The resultant solution is dried over anhydrous sodium sulfate and stripped of solvent by vacuum distillation. The residual oil is added to 25 parts of boiling ethyl acetate, from which 3 B-acetoxy- 2l-diethylamino 20 methyl-Sa-pregn-17(20)-ene hydrochloride crystallizes as it cools. The product melts at 230- 233,

EXAMPLE 11 2l-Diethylamino-20-methyl-3fi-propionyloxy-5a-pregn- 17 (20) -ene A mixture of 1 part of 21-diethylarnino-20-methyl-5apregn-17(20)-en-3;3-ol, 8 parts of propionic acid anhydride, 10 parts of pyridine, and 10 parts of chloroform is allowed to stand at room temperatures overnight, whereupon 100 parts of methanol is introduced. Solvent is removed by vacuum distillation, and the residue is taken up in 100 parts of Water. To the aqueous solution is added 5 parts of potassium carbonate. The precipitate which forms is 21-diethylamino-20-methyl-3fi-propionyloxy-5apreg n-l7(20)-ene, which is isolated by filtration and dried m an.

EXAMPLE 12 21-Dimethylamino-ZO-methyl-Sou-pregn-17 (20)-en-3-one hydrochloride To a solution of 12 parts of N,N-dimethyl-3-oxo-5apregn-17 (20)-ene-20-carboxamide and 20 parts of triethyl orthoformate in 60 parts of dioxane and 32 parts of absolute ethanol at 0 is added approximately 1 part of ptoluenesulfonic acid monohydrate. The resultant solution is stirred for /2 hour, whereupon 8 parts of pyridine is added and the solution thus obtained is poured into 4000 parts of water. The suspension which eventuates is extracted with 800 parts of benzene. The benzene extract is dried over anhydrous sodium sulfate and stripped of solvent by vacuum distillation. The residue is taken up in 400 parts of tetrahydrofuran, and to this solution is carefully added 12 parts of lithium tetrahydroaluminate(1-). The resultant mixture is heated at the boiling point under reflux overnight, whereupon 40 parts of ethyl acetate is introduced. The mixture thus obtained is poured into 4000 parts of 5% hydrochloric acid; and the resultant mixture is extracted with 4000 parts of chloroform. The chloroform extract is dried over anhydrous sodium sulfate and stripped of solvent by vacuum distillation, The residue is 21-dimethyla-mino 20 methyl-5a-pregn-l7(20) -en-3-one hydrochloride.

EXAMPLE 13 21-Diethylamino-Z0-methyl-5u-pregn-17(20) -en- 3-one hydrochloride Substitution of 12 parts of N,N-diethyl-3-oxo-5u-pregn- 17(20)-ene-20-carboxamide for the N,N-dimethyl-3-oxo- 5a-pregn-17(20)-ene-20-canboxamide called for in Example 12 affords, by the procedure there detailed, 21-diethylamino 20-methyl-5a-pregn-17(20)-en-3-one hydrochloride. The product, upon recrystallization from ethyl acetate, melts at 221-226".

7 What is claimed is: 1. A compound of the formula H36 (CH CHzN (lower alkyl) 2 wherein Z represents B-(lower alkanoyloxy)methylene, 5

fl-hydroxymethylene, or carbonyl.

2. A compound according to claim 1 having the formula H CIXCHQCHQN (lower alkyl):

3. A compound according to claim 1 which is 21-di- 3O ethylamino-20-methyl-5a-pregn-17(20) -en-3fi-ol.

4. A compound according to claim 1 having the formula H3O IC(CH;)CH1N (lower alkyl);

lower alkanoyl-O 5. A compound according to claim 1 which is 3 8- acetoxy-2l-diethylamino-20-methyl-5rx-prcgn-17(20)-ene.

6. A compound according to claim 1 having the formula H3 0 C (CHQCHlN (lower alkyl);

7. A compound according to claim 1 which is 21-diethylamino-ZO-methyl-Sa-pregn-l7(20) -en-3-one.

8. A compound of the formula H 0 0 (CH CON(lowcr alkyl):

wherein Z represents B-(lower a1kanoyloxy)methylene, phydroxymethylene, or carbonyl.

9. A compound according to claim 8 having the formula H 0 C (CH;) 0 ON (lower alkyl) 2 H 0 0 (CH3) 0 ON(lower alkylh 12. A compound according to claim 8 which is N,N- diethyl-3fi-hydIQXy-Su-pregn- 17 (2O -ene-20-carboxamide.

13. A compound according to claim 8 having the formula H 0 0 (CH C ON(l0wer alkyl):

14. A compound according to claim 8 which is N,N diethyl-3-oxo-5a-pregn-1 7 20) -ene-20-carboxamide.

No references cited.

HENRY A. FRENCH, Primary Examiner US. Cl. X.R. 

